It is a common practice in automotive vehicles to illuminate instrument clusters including illuminated gauge pointers. An instrument cluster includes a face plate bearing indicia for dials and other displays, and gauges behind the face plate which drive pointers across the dials. Generally the face plate is fashioned to serve as a light pipe to direct light from a number of strategically placed lamps to the pointers. The pointers comprise light pipes to carry the light along their length for clear viewing. The face plate itself may comprise a polycarbonate substrate for such light conduction. Each type of cluster requires custom design to achieve proper illumination of each portion of the display. The constraint of providing light to the pointers via the light pipe arrangement makes the design difficult and limits the choice of materials, and the displays are sometimes expensive to manufacture.
In addition to simplifying the illumination of pointers, it is also desirable to enhance the pointer illumination to exhibit different colors in different ranges so that, for example, a warning is given for a certain pointer range.